2
Function
Festo – CPX-E-PB-EN – 2017-07 – English
9
2.2
Address assignment
The system CPX-E is composed of a different number of inputs and outputs, depending on the number and type of
modules CPX-E used and the parameterisation of the bus module. The inputs and outputs are assigned
automatically within the system CPX-E.
The address assignment (number of allocated inputs and outputs) on the system CPX-E must be determined prior to
commissioning.
–
A maximum of 10 I/O m bus module is permitted in one system CPX-E.
–
The address space of a system CPX-E is limited. The bus module provides the system CPX-E with
amaximum address space of 64 bytes for inputs and 64 bytes for outputs.
–
Activated diagnostic functions like status bits or the I/O diagnostic interface reduce the number of
inputs and/or outputs in the available address space.
2.3
Addressing
2.3.1
Basic rules for addressing
–
The address assignment of the inputs does not depend on the address assignment of the outputs.
–
The counting mode is module-oriented from left to right.
–
The bus module counts as a module with 0 inputs and 0 outputs when the status bits and the I/O diagnostic
interface are deactivated.
–
Activated status bits occupy 8 inputs.
–
An activated I/O diagnostic interface occupies 16 inputs and 16 outputs.
2.3.2
Addressing example
1
Bus module CPX-E-PB
–
Status bits activated
–
I/O diagnostic interface deactivated
2
Digital input module CPX-E-16DI
3
Digital output module CPX-E-8DO
4
Digital output module CPX-E-8DO
5
Analogue input module CPX-E-4AI-U-I
6
Analogue output module CPX-E-4AO-U-I
Module no.:
0
1
2
3
4
5
1
2 3 4 5 6
Fig. 2.3
The address assignment for the system CPX-E presented is shown in Tab. 2.5.
Module no. Module
Input address
Output address
0
Bus module CPX-E-PB (with status bits)
E0 … E7
–
1
Digital input module CPX-E-16DI
I8 … I23
–
2
Digital output module CPX-E-8DO
–
A0 … 7
3
Digital output module CPX-E-8DO
–
A8 … 15
4
Analogue input module CPX-E-4AI-U-I
I24 … I87
–
5
Analogue output module CPX-E-4AO-U-I
–
O16 … O79
Tab. 2.5
